1. Field of the Invention
The present invention relates to a drum-integrated electric parking brake which is electrically operated by an actuator to generate a parking brake force. More specifically, it relates to a drum-integrated electric parking brake which can reduce the weight and manufacturing cost and improve the marketability compared to an existing caliper-integrated electric parking brake.
2. Description of Related Art
In general, a parking brake for a vehicle is used to stop the vehicle on the road or ground during parking and includes a foot brake and a hand brake. Typically the hand brake is used in small vehicles and the foot brake is used in midsize and large vehicles.
As well known in the art, according to a conventional parking brake system, when a driver operates a parking lever provided in the vehicle, a parking cable pulls an operation lever of a rear drum brake and, at this time, a lining connected to the operating lever extends and presses a drum, thereby braking the wheels of the vehicle using a frictional force between the drum and the lining.
In more detail, according to the conventional parking brake system, when the parking cable is pulled by the parking lever, the operating lever attached to one lining in a drum brake is pulled in conjunction with the parking cable and, at this time, the lining extends from the center of the lining and comes into close contact with the friction surface of the drum, thereby parking the vehicle.
As such, according to the conventional parking brake system which provides the braking of the wheels by the operation of the parking lever, the driver should operate the parking lever by hand during each parking, which is very inconvenient. Moreover, the driver may forget to operate the parking lever during parking, and thus the risk of safety accidents may increase.
Therefore, an electric parking brake (EPB) has recently been developed and used, which can facilitate the parking operation using driving force of a motor during parking and safely maintain the parking state, thereby eliminating the inconvenience of the manual parking brake system. According to the electric parking brake, when a driver pushes an operation button in the vehicle to drive the motor, the packing cable is pulled by the rotation of the motor, and thus a uniform braking force is applied to each vehicle.
FIG. 1 is a diagram showing a conventional caliper-integrated electric parking brake which is configured by mounting a motor 2 on a caliper 1, in which a screw in front of the motor pushes a lining of a drum brake to come into close contact with the friction surface of the drum, thereby generating a parking brake force.
However, the conventional caliper-integrated electric parking brake uses the expensive caliper, and thus the material cost increases, which reduces the economic efficiency. Moreover, the conventional caliper-integrated electric parking brake is relatively heavy and thus is difficult to be applied to low-cost vehicles.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.